Sakhir, Bahrain - Germany's Timo Glock was fastest in final practice for Sunday's Formula One Bahrain Grand Prix but then developed a problem with his Toyota ahead of qualifying later in the day. Ferrari's Felipe Massa of Brazil was second fastest, ahead of Williams driver Nico Rosberg, who had been quickest in the previous day's second practice.

World champion Lewis Hamilton of Braitain in a McLaren-Mercedes was fourth, with former world champiom Kimi Raikkonen of Finland in a Ferrari fifth.

With temperatures reaching around 38 degrees at the Bahrain International Circuit, Glock posted 1 minute 32.605 seconds before his car came to a stop with what was thought to be an electrical problem.

Overall leader Jenson Button of Britain was 15th, one place ahead of Brawn GP team-mate Rubens Barrichello of Brazil.

Qualifying later in the day will determine grid positions for Sunday's race, the fourth of the season.(dpa)